Extensible watch strap or bracelet



Sept. 28, 1965 A, HEINZ 3,208,211

EXTENSIBLE WATCH STRAP OR BRACELET Filed Feb. 1, 1962 2 Sheets-Sheet 1 INVENTOR 4185?) Ill-7W1 Sept. 28, 1965 A. HEINZ 3,208,211

EXTENSIBLE WATCH STRAP OR BRACELET Filed Feb. 1, 1962 2 Sheets-Sheet 2 I N VEN TOR flaewr 1/5/12 BY $10 M a ATTORNEYS United States Patent 3,208,211 EXTENSIBLE WATCH STRAP OR BRAGELET Albert Heinz, Hercyniastrasse 91, Pforzheirn, Germany Filed Feb. 1, 1962, Ser. No. 17%,362 Claims priority, appiication Germany, Feb. 15, 1961,

14 claims. Zcr. 59-49 The present invention relates to an extensible watch strap or bracelet which is composed of a plurality of links which are flexibly connected to each other and are adapted to be drawn apart against the action of spring means.

The extensible watch straps or bracelets which are only provided with a single extensibility have the disadvantage that, due to their construction, they can only be extended to a limited extent. The shorter the individual links of these straps are, the smaller is also the degree of expansion of the entire strap. The individual links may therefore not be as short as might be desired for the sake of the appearance of the strap since the strap may then not be so far extended that it can be easily slipped over the hand. Most extensible straps of a simple construction can therefore be slipped over the hand only with difficulty.

Although watch straps are also known which have a greater extensibility because their links are connected to each other to form a scissorlike arrangement or by means of pivotatable brackets, these straps have the disadvantage that they have only a limited stability.

It is an object of the present invention to provide an extensible watch strap or bracelet (hereafter simply referred to as a strap) which overcomes the disadvantages of the watch straps of prior designs and has a very great extensibility in comparison to its total length and the length of its individual links, and which may therefore also be provided with very short links. A further object of the invention is to provide an extensible strap, the cross-sectional size and shape of which does not materially change even when fully extended and which therefore retains its closed appearance at all times.

According to the invention, these objects are attained by making each link of the strap of three parts which are adapted to telescope over or into each other and two of which form extensible or draw members between which the third part which limits the extent of the movement of the two other parts is inserted so as to be at least partly covered thereby. According to a preferred embodiment of the invention, only the two draw members are connected to each other by one or more springs, While the intermediate link member then only serves for connecting the two other parts directly to each other when the strap is in the extended position.

Another feature of the invention consists in making the intermediate connecting member and one of the draw members of each link of a U-shaped cross section extending in the longitudinal direction of the strap, and in inserting them in such a manner into each other that the longitudinal webs of these two members engage with and overlap each other, while their transverse webs which extend vertically to the longitudinal direction of the strap and determine the extensibility of each link as well as of the entire strap form the end surface of each link. The second draw member then surrounds these two U-shaped members either partly or entirely. This second draw member is preferably designed to cover the U-shaped members when the strap is in the contracted position and to form the outer visible part of the link which determines the appearance thereof. Another feature of the invention consists in designing the second draw member "ice in the form of a cover which overlaps the upper webs of the two U-shaped link members. For extending the strap, this cover is adapted to be partly withdrawn from the U-shaped link members in the longitudinal direction of the strap and these members may be drawn apart to a certain extent. The individual members of each link are preferably held together and guided relative to each other by means of tabs which project from their edges and are bent over the edges of the adjacent link member. Some or all of these tabs may also serve as stop members for limiting the degree of expansion of the link.

According to another feature of the invention, the spring means which tend to maintain the three members of each link in the contracted position may be mounted within the connecting member and act upon the cover and upon the U-shaped draw member to draw them toward each other. These spring means preferably consist of a single spring, particularly a leaf or wire spring. For connecting the individual links to each other, the cover of each link may be provided on one outer transverse edge thereof with inwardly projecting tabs which engage behind the transverse web of the U-shaped draw member of the adjacent link. The U-shaped draw member is then preferably provided with slots through which the tabs on the cover of the adjacent link may be inserted.

These and further objects, features, and advantages of the present invention will become more clearly apparent from the following detailed description thereof, particularly when the same is read with reference to the ac companying drawings, in which- FIGURES 1 to 3 show perspective views of the three parts which together form one of the links of the strap according to the invention;

FIGURE 4 shows a perspective view of a contracted link which is composed of the parts according to FIG- URES 1 to 3;

FIGURE 5 shows a perspective view of the link according to FIGURE 4 in the extended position;

FIGURE 6 shows a cross section taken along line VI- VI of FIGURE 4, but with a spring inserted in the link;

FIGURE 7 shows a cross section taken along line VIL- VII of FIGURE 5, also with a spring inserted in the link and the link being connected to the adjacent links;

FIGURE 8 shows a cross section similar to that according to FIGURE 6, but in which the link is provided with a single leaf spring;

FIGURE 9 shows a perspective view of a link with parts thereof broken away to show a double leaf spring inserted therein;

FIGURE 10 shows a plan view of the spring according to FIGURE 9;

FIGURES 11 to 13 show perspective views of the three parts which together form a link according to a modification of the invention;

FIGURE 14 shows a perspective view of a contracted link which is composed of the parts according to FIG- URES 11 to 13;

FIGURE 15 shows a perspective view of the link according to FIGURE 15 in the extended position; while FIGURE 16 shows a part of a strap which is composed of links according to FIGURE 14.

In the drawings, FIGURES 4 and 5 illustrate one of the assembled links of the extensible strap according to the invention, while FIGURES 1 to 3 show the three individual members of such a link, namely, a draw member 1 forming a cover, a U-shaped intermediate connecting member 2, and a U-shaped draw member 3. The two ends of cover 1 are bent downwardly to form lateral wall portions 4 which extend in the longitudinal direction of the strap and are provided with a pair of tabs 5 which project beyond one transverse edge of the cover. Ad-

jacent to the opposite transverse edge of cover 1, wall portions 4 are provided with inwardly bent tabs 6 which are spaced from and extend parallel to the inner surface of cover 1. These tabs 6 together with the inner surface 'of cover 1 are adapted to guide the upper web 7 of the U-shaped connecting member 2 which may be inserted into cover 1 in the direction of the arrow 8. The U- shaped draw member 3 may be inserted in a similar manner into cover 1 in the direction of the arrow 9. The upper web 10 of draw member 3 is then disposed between cover 1 and the upper web 7 of the connecting member, while the lower web 11 of draw member 3 slides under the lower web 12 of connecting member 2. Draw member 3 also has a pair of tabs 15 projecting from the lateral ends of it slower web 11 and another tab 16 projecting from the center of the transverse edge of the upper web 10.

After the link members 1 to 3 have been assembled, they are in the position as illustratted in FIGURE 4. The transverse webs 13 and 14 of the U-shaped members 2 and 3 then form the end walls of the link which extend vertically to the longitudinal direction of the strap. After tabs 5, 15, and 16 have been bent over, the three link members 1, 2, and 3 are permenantly connected to each other, but in a manner so as to be slidable relative to each other in the longitudinal direction of the strap. The upper webs 7 and 10 of the U-shaped link members 2 and 3 are then guided between the cover 1 and its tabs 6, while the lower webs 11 and 12 of these members are connected to each other by the tabs 15. Tabs on cover 1 after being bent toward each other prevent the connecting link member 2 from being pulled out of the cover 1 'in the direction opposite to that of arrow 8.

FIGURE 5 illustrates the link in the fully extended position. Cover 1 may be drawn off the connecting member 2 in the longitudinal direction of the strap until the inwardly bent tabs 6 abut against the transverse web 13 of member 2. Tabs 6 together with the transverse web 13 therefore limit the distance to which the two link members 1 and 2 can be extended. Link members 2 and 3 may also be drawn away from each other in a similar manner until tabs 15 on the lower web 11 of draw member 3 abut against a web 17 which is bent upwardly from the transverse edge of the lower web 12 of the connecting member 2. In addition, tab 16 on the upper web of draw member 3 is bent downwardly and into an aperture 18 which is provided in the upper web 7 and also extends into the transverse web 13 of connecting member 2 so that when the link is in the fully extended position, tab 16 abuts against the transverse edge 19 of aperture 18 and thus also limits the extent of the expansion in the same manner as tab 15.

When the link is extended, as shown in FIGURE 5, the connecting member 2 lies substantially in the center of the entire link, while cover 1 and the U-shaped draw member 3 form the outer parts. Since webs 7 and 12 of connecting member 2 are inserted between webs 10 and 11 of draw member 3, the lower web 11 of the latter also forms the bottom plate of the link. When the strap is extended and each link is in the position as shown in FIGURE 5, cover 1 is directly connected only to the U-shaped connecting member 2 and the latter, in turn, only to the U-shaped draw member 3. Thus, the three link members form a chain, and the two draw members 1 and 3 are connected to each other only indirectly through the connecting member. This fact that there is no direct connection between the two draw members of each link which limits the extent of its expansion, that is, between the cover 1 and the U-shaped draw member 3, is the principal cause for the great extensibility of the strap according to the invention which amounts to approximately 100% when the links are of a construction as illustrated in FIGURES 1 to 5. In actual practice, however, tabs 6 and will usually be made of such a width that the expansion of each link will be terminated before cover 1 is drawn off completely from the upper web 10 of the U-shaped draw member 3 so that the strap will retain its good appearance even when completely expanded. The connecting member 2 when seen from above then remains completely covered by the draw members 1 and 2 even when the strap is completely extended which thus retains its good closed appearance at all times. The good appearance of the strap according to the invention is also partly due to the fact that its thickness practically does not change when it is expanded. Even though its extensibility is limited as just mentioned, the strap may be extended to an extent of about which is in any event sufiicient and far exceeds the extensibility of the straps of prior designs.

While cover 1 and the U-shaped draw part 3 are not directly connected to each other, the spring means which are required for drawing the strap together only act upon these two draw members of each link. The cross sectional views according to FIGURES 6 and 7 illustrate a bent leaf or wire spring which is preferably employed in a link of the type as shown in FIGURES 1 to 5. This spring 20 has two free arms 21 which cross each other and are connected by a bail-shaped part 22. Spring 20 is disposed within the connecting member 2 in such a manner that the ends of their free arms engage upon the inwardly bent tabs 6 of cover 1, while the bail-shaped part 22 of the spring engages upon tab 16 of the U-shaped draw member 3 which extends through the aperture 18 in the wall of connecting member 2. For securing the arms 21 of spring 20 to the tabs 6, the latter are provided with slots 23. Spring 22 has the tendency always to shift the cover 1 entirely over the U-shaped draw member 3 so that the individual parts of the link always tend to assume the position as illustrated in FIGURE 4. The connecting member 2 which is enclosed and freely suspended between cover 1 and the draw member 3 is then held firmly between the two draw members 1 and 3.

When the link is extended, tabs 6 move along the edges of the upper web 7 of connecting member 2 until they engage against the transverse web 13 of member 2, while tab 16 of draw member 3 is shifted in the opposite direction until it engages against the transverse edge 19 of aperture 18 in the connecting member 2. When the link is being extended to its fully extended position, as shown in FIGURE 7, tabs 6 therefore move past tabs 16, whereby the arms 21 of spring 20 are drawn beyond tab 16 to the position as shown which is possible because of the particular shape of the spring.

Tabs 5 on cover 1 not only serve for enclosing the connecting member 2 but also for connecting the link to the adjacent link of the strap. As also indicated in FIGURE 7, tabs 5' of cover 1 of the adjacent link at the right side engage behind the transverse web 14 of the U-shaped draw member 3, and tabs 5 of cover 1 engage in the same manner behind the transverse web 14 of the U-shaped draw member 3" of the link at the left side of FIGURE 7. For hooking the tabs 5 or 5 into the draw members 3 or 3", the upper webs 10 or 10" thereof are provided with slots 24 or 24", respectively, which are spaced at such a distance from the transverse webs 14 or 14" that tabs 5' or 5 can be easily inserted when the links are in the expanded position. The adjacent links are, however, positively prevented from being unintentionally disconnected from each other since, when the strap is in the contracted position, slots 24 or 24" are covered by the cover of the respective link and, when the strap is being expanded, tabs 5' or 5 necessarily engage against webs 14 or 14". Of course, instead of providing the slots 24 in the upper web 10 of draw member 3, they may also be: provided in the lower web 11 thereof.

Especially if the extensible strap consists of very short links, a slightly bent wire or leaf spring 25, as shown in FIGURE 8, may be employed in place of spring 20, as. shown in FIGURES 6 and 7. The free arms of this spring 25 also engage on tabs 6 of cover 1, while its central part engages on tab 16 of the U-shaped draw member 3. The,

springs according to FIGURES 6 to 8 may be hooked into the cover of the respective link before the individual parts thereof are assembled and they will then assume their proper position automatically.

FIGURES 9 and 10 illustrate another preferred modification of the spring which consists of two curved parts 27 and 28 which are connected to each other at the center by an angular web 26 and the arms of which are bent in opposite directions so as to intersect each other. Web 26 is made of such a shape that one of the two curved parts is disposed above the other. The ends of the upper part 27 engage in the same manner as those of the springs as previously mentioned on tab 6 of cover 1, and the ends of the lower spring part 28 also engage on tabs which are provided on the lower web 11 of draw member 3. In this case, tab 16 on the upper web 10 of the U-shaped draw member 3 and aperture 18 in connecting member 2 may therefore be omitted. The spring according to FIG- URES 9 and 10 may likewise be easily inserted into the link when the individual parts thereof are in the contracted position. All other parts of the links according to FIGURES 8 to 10 except the springs are similar to those in FIGURES 1 to 7 and are therefore identified by the same reference numerals as applied in FIGURES l to 7.

FIGURES 14 and 15 illustrate a modification of a link for an extensible strap according to the invention. This link is again composed of a draw member 31 in the form of a cover, a U-shaped connecting member 32 which limits the extent of the expansion of the link, and a U- shaped draw member 33, as separately illustrated in FIG- URES 11 to 13. Cover 31 like cover 1 as previously described has a pair of tabs 34 which extend beyond one transverse edge of the cover and are bent toward each other after the different parts of the link are asembled. Cover 31 is provided with two further tabs 35 which engage around the upper webs 36 and 37 of the U-shaped members 32 and 33 after the latter are inserted into cover 31, as illustrated in FIGURE 14. Draw member 33 is similar to draw member 3 and also has on its transverse front edge a tab 38 which is bent downwardly and into an aperture 39 in the connecting member 32 after the different parts of the link are assembled. The link according to FIGURES 14 and 15 differs, however, from the link according to FIGURES 4 and 5 by the fact that the upper web 37 as well as the lower web 40 of draw member 33 are located above webs 36 and 41 of connecting member 32 so that the lower web 41 of the latter forms the bottom plate of the link. Consequently, the lower web 41 of connecting member 32 is not provided with a transverse web at the right-side transverse edge thereof but with lateral inwardly bent tabs 42 which take the place of tabs 15 of draw member 3 according to FIG URE 3. As indicated in FIGURE 12, these tabs 42 may, however, be bent inwardly before the different parts of the link are assembled. This facilitates the assembly of the link according to FIGURES l4 and 15. This link construction also has the advantage that tabs 35 and 42 do not have to pass each other when the strap is being expanded but that they face each other when the strap is in the contracted position. This permits the cover 31 of the link to be provided with practically closed lateral surfaces, as illustrated in FIGURE 16, so that this strap may have a still more pleasing appearance than the one previously described.

The means for drawing the link members according to FIGURES 11 to 13 together to the position as shown in FIGURE 14 may consist of springs similar to those as illustrated in FIGURES 6 to 8.

For connecting the different links of a strap to each other, cover 31 of each link is also in this case provided with tabs 34 which are hooked behind the transverse 43 of draw member 33 of the adjacent link. For this purpose, draw member 33 is provided with slots 44 at a point adjacent to the edge between the transverse Web 43 and the lower web 40. For inserting tabs 34 into slots 44, the two adjacent links to be connected must be held substantially at a right angle relative to each other. Since this will practically never occur while the strap is in use, the individual links are also in this case prevented from being unintentionally unhooked from each other. For special security, tabs 34 may be additionally provided with a small nose 45 which is projecting toward the left, as shown in FIGURE 15, while slot 44 is provided with a corresponding angular extension 46 so that tabs 34 of one link can be passed through slots 44 of the adjacent link only if they are moved exactly parallel to the lower web 40 of draw member 33 of the adjacent link. Of course, also in this strap it is possible to provide the slots for the insertion of tabs 34 in the upper web 37 or better in the lower web 41) of draw member 33.

FIGURE 16 illustrates the contracted position of a part of an extensible watch strap or bracelet which is composed of links similar to those as shown in FIGURES 14 and 15. Of the individual parts of the links practically no more is visible than the covers 31 which are extended so far in the longitudinal direction of the strap that they cover tabs 34 completely. The U-shaped connecting member 32 is visible only by its lower web 41 with tabs 42 thereon which are opposite to tabs 35 on cover 31 and are separated therefrom by a narrow slot. FIGURE 16 further shows a part of the U-shaped draw member 33 which is especially noticeable on the right end link of the watch strap as illustrated. The upper surfaces of covers 31 may be either flat, arched, or of any other desired shape or design and may also be embellished in any desired manner. It is also a special advantage of the strap according to the invention that the covers may be made independently of the parts forming the bottom plates and may therefore consist of a material different from that of the bottom plates. This permits gold or gold-plated watch straps with a bottom of stainless steel to be very easily made.

The number of individual links according to the invention which may be connected to each other is entirely optimal. It is thus possible to produce extensible straps of any desired length the ends of which may 'be either connected to each other to form bracelets or the like or be provided with suitable end links which may be connected to watches to form watch straps.

Although my invention has been illustrated and described with reference to the preferred embodiments thereof, I wish to have it understood that it is in no way limited to the details of such embodiments but is capable of numerous modifications within the scope of the appended claims.

Having thus fully disclosed my invention, what I claim is:

1. An extensible watch strap or bracelet comprising a plurality of links pivotably connected to each other and each link comprising three link members telescopically slidable relative to each other, two of said members forming draw members adapted to be drawn apart from a contracted position to an extended position of said link, and the third member forming a connecting member inserted between and slidably connecting said draw members to each other and determining the length to which said link may be extended, said draw members covering the upper side of said connecting member, and spring means tending to maintain said link in the contracted position, said link members being in superposed relationship to each other.

2. An extensible watch strap or bracelet comprising a plurality of links pivotably connected to each other and each link comprising three link members telescopically slidable relative to each other, two of said members forming draw members adapted to be drawn apart from a contracted position to an extended position of said link, and the third member forming a connecting member inserted between and slidably connecting said draw members to each other and determining the length to which said link may be extended, said draw members covering the upper side of said connecting member, and spring means tending to maintain said link in the contracted position, said spring means being disposed substantially Within said connecting member and engaging with and acting in opposite directions upon said draw members, said link members being in superposed relationship to each other.

3. An extensible watch strap or bracelet comprising a plurality of links pivotably connected to each other and each link comprising three link members telescopically slidable relative to each other, two of said members forming draw members adapted to be drawn apart from a contracted position to an extended position of said link, and the third member forming a connecting member inserted between and slidably connecting said draw members to each other and determining the length to which said link may be extended, the first of said draw members and said connecting member each having a U- shaped cross section with a pair of free webs and a transverse web connecting the same, said free webs extending in the longitudinal direction of said strap and slidable into each other so as to be substantially in engagement with and to overlap each other, said transverse webs extending substantially vertical to the longitudinal direction of said strap and forming the end surfaces of said link, the second draw member at least partly surrounding said U-shaped members, said draw members covering the upper side of said connecting member, and spring means connecting said draw members to each other and tending to maintain said link in the contracted position.

4. An extensible watch strap or bracelet comprising a plurality of links pivotably connected to each other and each link comprising three link members telescopically slidable relative .to each other, two of said members forming draw members adapted to be drawn apart from a contracted position to an extended position of said link, and the the third member forming a connecting member inserted between and slidably connecting said draw members to each other and determining the length to which said link may be extended, the first of said draw members and said connecting member each having a U-shaped cross section with a pair of free webs and a transverse web connecting the same, said free webs extending in the longitudinal direction of said strap and slidable into each other so as to be substantially in engagement with and to overlap each other, said transverse webs extending substantially vertical to the longitudinal direction of said strap and forming the end surfaces of said link, the second draw member at least partly surrounding said U-shaped members, said draw members covering the upper side of said connecting member, and said second draw member forming a cover disposed above said U-shaped members and overlapping the upper webs thereof when the strap is in the contracted position, thus forming the outer visible part of said link, and spring means connecting said draw members to each other and tending to maintain said link in the contracted position.

5. An extensible watch strap or bracelet comprising a plurality of links flexibly connected to each other and each link comprising three link members telescopically slidable relative to each other, two of said members forming draw members adapted to be drawn apart from a contracted position to an extended position of said link, and the third member forming a connecting member inserted between and slidably connecting said draw members to each other and determining the length to which said link may be extended, the first of said draw members and said connecting members each having a U-shaped cross section with a pair of free upper and lower webs and a transverse web connecting the same, said free webs extending in the longitudinal direction of said strap, said free webs of said connecting member being inserted and slidable between said free webs of said first draw member, the lower web of said first draw member forming the bottom plate of said link, said transverse webs extending substantially vertical to the longitudinal direction of said strap and forming the end surfaces of said link, said second draw member at least partly surrounding said U-shaped members, and spring means connecting said draw members to each other and tending to maintain said link in the contracted postion.

6. An extensible watch strap or bracelet comprising a plurality of links flexibly connected to each other and each link comprising three link members telescopically slidable relative to each other, two of said members forming draw members adapted to be drawn apart from a contracted position to an extended postion of said link, and the third member forming a connecting member inserted bet-ween and slidably connecting said draw members to each other and determining the length to which said link may be extended, the first of said draw members and said connecting members each having a U-shaped cross section with a pair of free upper and lower webs and a transverse web connecting the same, said free webs extending in the longitudinal direction of said strap, said free webs of said first draw member being disposed above and slidable along said free webs of said connecting member, the lower Web of said connecting member forming the bottom plate of said link, said transverse Webs extending substantially vertical to the longitudinal direction of said strap and forming the end surfaces of said link, said second draw member at least partly surrounding said U-shaped members, and spring means connecting said draw members to each other and tending to maintain said link in the contracted position.

7. An extensible watch strap or bracelet comprising a plurality of links pivotably connected to each other and each link comprising three link members telescopically slidable relative to each other, two of said members forming draw members adapted to be drawn apart from a contracted position to an extended position of said link, .and the third member forming a connecting member inserted between and slidably connecting said dra'w members to each other and determining the length to which said link may be extended, said draw members covering the upper side of said connecting member, tabs projecting from the edges of each of at least two of said link members and bent around the edges of the adjacent link member for holding said link members together, at least some of said tabs forming stop members for limiting the degree of extension of said link, and spring means connecting said draw members to each other and tending to maintain said link in the contracted position.

'8. An extensible watch strap or bracelet com-prising a plurality of links pivotably connected to each other and each link comprising three link members telescopically slidable relative to each other, two of said members forming draw members adapted to be drawn apart [from a contracted position to an extended position of said link, and the third member forming a connecting member inserted bet-ween and slidably connecting said draw members to each other and determining the length to which said link may be extended, the first of said draw members and said connecting member each having a U-shaped cross section with a pair of free upper and lower webs and a transverse web connecting the same, said free webs extending in the longitudinal direction of said strap and slidable into each other so as to be substantially in engagement with and to overlap each other, said transverse webs extending subtantially vertical to the longitudinal direction of said strap and forming the end surfaces of said link, the second draw member at least partly surrounding said U-shaped members, said draw members covering the upper side of said connecting member, and said second draw member forming a cover disposed above said U-shaped members and covering the same when the strap is in the contracted position, thus forming the outer visible part of said link, said second draw member having tabs on both lateral longitudinal edges each being bent downwardly and then inwardly toward the corresponding tab and thus around the corresponding longitudinal edges of the upper webs of said U-shaped members and abutting against the transverse web of said connecting member when the strap is extended to limit the degree of extension of said link, and spring means, connecting said draw members to each other and tending to maintain said link in the contracted position.

9. An extensible watch strap or bracelet comprising a plurality of links flexibly connected to each other and each link comprising three link members telescopically slidable relative to each other, two of said members forming draw members adapted to be drawn apart from a contracted position to an extended position of said link, and the third member forming a connecting member inserted between and slidably connecting said draw members to each other and determining the length to which said link may be extended, the first of said draw members and said connecting members each having a U-shaped cross section with a pair of free upper and lower webs and a transverse web connecting the same, said free webs extending in the longitudinal direction of said strap, said free webs of said connecting member being slidable relative to said free webs of said first draw member, the lower web of one of said U-shaped members forming the bottom plate of said link and having tabs on its longitudinal edges each being bent upwardly and then inwardly toward corresponding tab and thus around the longitudinal edges of the lower web of the other U-shaped member, the free transverse edge of the lower web of said other U-shaped member having at least one projection thereon, said tabs abutting against said projection when the strap is extended, thus limiting the degree of extension of said link, said transverse webs extending substantially vertical to the longitudinal direction of said strap and forming the end surfaces of said link, said second draw member at least partly surrounding said U-shaped members, and spring means connecting said draw members to each other and tending to maintain said link in the contracted position.

10. An extensible watch strap or bracelet compris ing a plurality of links pivotally connected to each other and each link comprising three link members telescopically slidable relative to each other, two of said members forming draw members adapted to be drawn apart from a contracted position to an extended position of said link, and the third member forming a connecting member inserted between and slidably connecting said draw members to each other and determining the length to which said link may be extended, the first of said draw members and said connecting member each having a U-shaped cross section wtih a pair of tree webs and a transverse web connecting the same, said free webs extending in the longitudinal direction of said strap and slidable into each other so as to be substantially in engagement with and to overlap each other, said transverse webs extending substantially vertical to the longitudinal direction of said strap and forming the end surfaces of said link, the second draw member at least partly surrounding said U- shaped members, said draw members covering the upper side of said connecting member, and said second draw member forming a cover disposed above said U-shaped members and covering the same when the strap is in the contracted position, thus forming the outer visible part of said link, said second draw member having tabs on both lateral longitudinal edges each being bent downwardly and then inwardly toward the corresponding tab and thus around the corresponding longitudinal edges of the upper webs of said U-shaped members and abutting against the transverse web of said connecting member when the strap is extended to limit the degree of extension of said link, said connecting member having at least one aperture at least in the upper web thereof, the free transverse edge of the upper web of said first draw member having at least one downwardly projecting tab thereon engaging into said aperture, and a single spring having free arms connecting said draw members to each other and tending to maintain said link in the contracted position, the ends of said spring arms engaging with and acting upon said tabs on the longitudinal edges of said second draw member, the central part of said spring engaging with and acting upon said downwardly projecting tab on said first draw member.

11. An extensible watch strap or bracelet comprising a plurality of links pivotably connected to each other and each link comprising three link members telescopically slidable relative to each other, two of said members forming draw members adapted to be drawn apart from a contracted position to an extended position of said link, and the third member forming a connecting member inserted between and slidably connecting said draw members to each other and determining the length to which said link may be extended, said draw members covering the upper side of said connecting member; one of said draw members comprising oppositely disposed downwardly extending end wall portions, tab members on said wall portions extending angularly thereto, the other of said draw members comprising lateral edge portions joined by a connecting edge portion, a further tab portion projecting downwardly from said connecting edge portion, and a single curved spring of a type comprising a leaf spring, wire spring and the like substantially disposed within said connecting member and engaging with and acting in opposite directions upon said draw members and tending to maintain said link in a contracted position, said spring comprising an intermediate portion in engagement with said further tab portion, said spring further comprising slightly curved end portions extending from said further tap portion in the directions of said tab members, said end portions being secured at their ends to said tab members.

12. An extensible watch strap or bracelet comprising a plurality of links pivotally connected to each other and each link comprising three link members telescopically slidable relative to each other, two of said members forming draw members adapted to be drawn apart from a contracted position to an extended position of said link, and the third member forming a connecting member inserted between and slidably connecting said draw members to each other and determining the length to which said link may be extended, said draw members covering the upper side of said connecting member, and a single curved spring of a type comprising a leaf spring, wire spring and the like substantially disposed within said connecting member and connected at its center to one of said draw members and having two arms extending from said center, said spring being curved so that said spring arms cross each other, the free ends of said arms being connected to the other of said draw members.

13. An extensible watch strap or bracelet comprising a plurality of links pivotably connected to each other and each link comprising three link members telescopically slidable relative to each other, two of said members forming draw members adapted to be drawn apart from a contracted position to and extended position of said link, and the third member forming a connecting member inserted between and slidably connecting said draw members to each other and determining the length to which said link may be extended, said draw members covering the upper side of said connecting member, and spring means comprising two springs curved in opposite directions to each other and the free ends of one of said springs engaging with and acting in one direction upon one of said draw members and the free ends of the other spring engaging with the acting in the opposite direction upon the other draw member, and means for securing said springs to each other at the center thereof.

14. An extensible watch strap or bracelet comprising a plurality of links pivotably connected to each other and each link comprising three link members telescopically slidable relative .to each other, two of said members forming draw members adapted to be drawn apart from a contracted position to an extended position of said link, and the third member forming a connecting member inserted between and sh'dably Connecting said draw members to each other and determining the length to which said link may be extended, the first of said draw members and said connecting member each having a U- shaped cross section with a pair of free webs and a transverse web connecting the same, said free webs extending in the longitudinal direction of said strap and slidable into each other so as to be substantially in engagement with and to overlap each other, said transverse webs extending substantially vertical to the longitudinal direction of said strap and forming the end surfaces of said link, the second draw member at least partly surrounding said U-shaped members, said draw members covering the upper side of said connecting member, and said second draw member forming a cover disposed above said U-shaped members and covering the same when the strap is in the contracted position, thus forming the outer visible part of said link, said second draw member having tabs on both lateral longitudinal edges adjacent to one transverse edge thereof each being bent downwardly and then inwardly toward the corresponding tab and thus around the corresponding longitudinal edges of the upper webs of said U-shaped members and abutting against the transverse web of said connecting member when the strap is extended to limit the degree of extension of said link, said first draw member having slots in one of its webs extending toward each other from both lateral sides thereof, said second draw member having further tabs on both lateral sides adjacent to its other transverse edge and bent inwardly toward each other, said last tabs on the seoond draw member of one link being adapted to be inserted into said slots in said first draw member of the adjacent link and then to be placed behind the transverse web of said first draw member of said adjacent link for pivotably connecting two adjacent links to each other, and spring means connecting said draw members of each link to each other and tending to maintain said link in the contracted position.

References Cited by the Examiner UNITED STATES PATENTS 787,639 4/05 Rioux 1 5979 2,985,999 5/61 Knopp 5979 FOREIGN PATENTS 107,464 7/17 Great Britain.

CHARLES W. LANHAM, Primary Examiner. 

1. AN EXTENSIBLE WATCH STRAP OR BRACELET COMPRISING A PLURALITY OF LINKS PIVOTABLY CONNECTED TO EACH OTHER AND EACH LINK COMPRISING THREE LINK MEMBERS TELESCOPICALLY SLIDABLE RELATIVE TO EACH OTHER, TWO OF SAID MEMBERS FORMING DRAW MEMBERS ADAPTED TO BE DRAWN APART FROM A CONTRACTED POSITION TO AN EXTENDED POSITION OF SAID LINK, AND THE THIRD MEMBER FORMING A CONNECTING MEMBER INSERTED BETWEEN AND SLIDABLY CONNECTING SAID DRAW MEM- 